1. Field of the Invention
The invention generally relates to acoustical and/or mechanical vibrational based methods that increase tissue blood flow and oxygenation. In particular, the invention provides methods and equipment for the use of low frequency sound or mechanical vibration to increase blood flow and hence tissue oxygenation. The methods are useful for the treatment or prevention of disorders related to ischemia and low blood flow.
2. Background of the Invention
Pathological conditions associated with decreased or low blood flow (ischemia) kill or incapacitate millions of people annually. Examples of such conditions include hemorrhagic shock, cardiogenic shock, congestive heart failure, cardiac arrest, septic shock, intestinal ischemia, myocardial ischemia, stroke, traumatic brain injury, sickle cell vaso-occlusive crisis, burns, compartment syndrome, and acute and chronic wounds, among others. In these cases, ischemia can cause rapid, irreversible damage or death of the affected tissue. In addition, chronic, non-acute low blood flow has been implicated in the development of progressive diseases such as osteoporosis.
To date, the major means to modulate blood flow to organ systems has been with the use of pharmaceutical agents delivered intravenously. These have taken the form of intravenous fluids, vasopressors, and vasodilators. Alternatively, invasive devices such as the intra-aortic balloon pump have been used. These methods are invasive and associated with various complications. Recent interest has been demonstrated in modulating blood flow pharmacologically using the nitric oxide pathway but there are currently no approved uses for such with the exception of inhaled nitric oxide for severe pulmonary hypertension.
U.S. Pat. No. 6,155,976 to Sackner et al. (Dec. 5, 2000) describes a bed or device which produces periodic Gz acceleration. This is a mechanical device which shakes or moves the subject at a certain frequency in a head to toe direction. It has been studied for use in cardiac arrest and improved blood flow. The mechanism by which it improves flow is believed to be based on these shaking movements causing an increase in nitric oxide production. However, this device is not portable, and cannot be readily adapted to emergency situations.
The prior art has thus far failed to provide non-invasive methodology for the prevention or treatment of low blood flow/ischemia, particularly methodology that can be readily employed in emergency situations.